/*
 *    DoubleVector.java
 *    Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
 *    @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package moa.core;

import moa.AbstractMOAObject;

public class DoubleVector extends AbstractMOAObject {

	private static final long serialVersionUID = 1L;

	protected double[] array;

	public DoubleVector() {
		this.array = new double[0];
	}

	public DoubleVector(double[] toCopy) {
		this.array = new double[toCopy.length];
		System.arraycopy(toCopy, 0, this.array, 0, toCopy.length);
	}

	public DoubleVector(DoubleVector toCopy) {
		this(toCopy.getArrayRef());
	}

	public int numValues() {
		return this.array.length;
	}

	public void setValue(int i, double v) {
		if (i >= this.array.length) {
			setArrayLength(i + 1);
		}
		this.array[i] = v;
	}

	public void addToValue(int i, double v) {
		if (i >= this.array.length) {
			setArrayLength(i + 1);
		}
		this.array[i] += v;
	}

	public void addValues(DoubleVector toAdd) {
		addValues(toAdd.getArrayRef());
	}

	public void addValues(double[] toAdd) {
		if (toAdd.length > this.array.length) {
			setArrayLength(toAdd.length);
		}
		for (int i = 0; i < toAdd.length; i++) {
			this.array[i] += toAdd[i];
		}
	}

	public void subtractValues(DoubleVector toSubtract) {
		subtractValues(toSubtract.getArrayRef());
	}

	public void subtractValues(double[] toSubtract) {
		if (toSubtract.length > this.array.length) {
			setArrayLength(toSubtract.length);
		}
		for (int i = 0; i < toSubtract.length; i++) {
			this.array[i] -= toSubtract[i];
		}
	}

	public void addToValues(double toAdd) {
		for (int i = 0; i < this.array.length; i++) {
			this.array[i] = this.array[i] + toAdd;
		}
	}

	public void scaleValues(double multiplier) {
		for (int i = 0; i < this.array.length; i++) {
			this.array[i] = this.array[i] * multiplier;
		}
	}

	// returns 0.0 for values outside of range
	public double getValue(int i) {
		return ((i >= 0) && (i < this.array.length)) ? this.array[i] : 0.0;
	}

	public double sumOfValues() {
		double sum = 0.0;
		for (double element : this.array) {
			sum += element;
		}
		return sum;
	}

	public int maxIndex() {
		int max = -1;
		for (int i = 0; i < this.array.length; i++) {
			if ((max < 0) || (this.array[i] > this.array[max])) {
				max = i;
			}
		}
		return max;
	}

	public void normalize() {
		scaleValues(1.0 / sumOfValues());
	}

	public int numNonZeroEntries() {
		int count = 0;
		for (double element : this.array) {
			if (element != 0.0) {
				count++;
			}
		}
		return count;
	}

	public double minWeight() {
		if (this.array.length > 0) {
			double min = this.array[0];
			for (int i = 1; i < this.array.length; i++) {
				if (this.array[i] < min) {
					min = this.array[i];
				}
			}
			return min;
		}
		return 0.0;
	}

	public double[] getArrayCopy() {
		double[] aCopy = new double[this.array.length];
		System.arraycopy(this.array, 0, aCopy, 0, this.array.length);
		return aCopy;
	}

	public double[] getArrayRef() {
		return this.array;
	}

	protected void setArrayLength(int l) {
		double[] newArray = new double[l];
		int numToCopy = this.array.length;
		if (numToCopy > l) {
			numToCopy = l;
		}
		System.arraycopy(this.array, 0, newArray, 0, numToCopy);
		this.array = newArray;
	}

	public void getSingleLineDescription(StringBuilder out) {
		getSingleLineDescription(out, numValues());
	}

	public void getSingleLineDescription(StringBuilder out, int numValues) {
		out.append("{");
		for (int i = 0; i < numValues; i++) {
			if (i > 0) {
				out.append("|");
			}
			out.append(StringUtils.doubleToString(getValue(i), 3));
		}
		out.append("}");
	}

	public void getDescription(StringBuilder sb, int indent) {
		getSingleLineDescription(sb);
	}

}
